Flexible shaft for manicuring machines



y 3, 1952 M. KESSLER 2,596,335

FLEXIBLE SHAFT FOR MANICURING MACHINES Filed Aug. 21, 1948 FVIE J L LI L FIE E w Pat ented May 13, 1952 FLEXIBLE SHAFT FOR MANICURING MACHINES Merrill Kessler, Oakland, Calif., assignor to Aristocrat Manicuring Company, a corporation of Nevada Application August 21, 1948, Serial No. 45,471

1 Claim. 1

The invention relates to power operated manicuring machines of the type utilizing an electric motor and a flexible drive shaft connected thereto and to which in turn may be connected one of a plurality of rotary manicuring instruments.

An object of the present invention is to provide a manicuring machine of the character described having an improved form of flexible drive which affords a smooth and steady driving of the rotary manicuring instrument attached thereto and permits such instrument to be easily held and manipulated in the hand of the operator for precise positioning upon and movement over the finger nail to be manicured, and wherein the usual tendency of the flexible drive to whip or move abruptly in the hand of the operator upon manipulation of the instrument is practically entirely eliminated.

Another object of the present invention is to provide a flexible drive arrangement in a manicuring machine of the character described which affords a simple and rapid changing of various manicuring instruments at the end of the flexible drive.

A further object of the invention is to provide a flexible drive assembly in a manicuring machine of the character described which may be manufactured as an operating unit of the machine and quickly and readily applied to or removed from the electric motor of the machine. Still another object of the invention is to provide a flexible drive assembly for a manicuring machine of the character described which is designed for long and continuous use, as where employed for commercial operations, and for constant interchanging of the rotary manicuring instruments during such use, without being sub- Ject to appreciable wear or lowering of its qualities of operation over a long period of use.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth in the following description of the preferred form of the invention which is illustrated in the drawing accompanying and forming part of the specification. It is to be understood, however, that variations in the showing made by the said drawing and description may be adopted within the scope of the invention as set forth in the claim.

Referring to said drawing:

Figure 1 is a side elevation of a flexible drive arrangement for a manicuring machine embodying the present invention.

Figure 2 is an enlarged cross-sectional view of the opposite ends of the flexible drive, with portions of the drive shown in elevation.

Figure 3 is a cross-sectional view taken substantially on the plane of line 3--3 of Figure 2.

The manicuring machine illustrated in the accompanying drawing includes an electric motor 6 having an exterior casing l secured in an appropriate manner to a base 8 and provided with a drive shaft 9 having an end II extended centrally through and journalled within a bearing boss I2 formed on one end [3 of the casing l.

Secured to the boss I2 and to the shaft end H and extended axially therefrom is a flexible drive, generally denoted by numeral I4, and which, in turn, is adapted to receive and drive at its outer end one of a plurality of manicuring instruments, the instrument [6 here shown being in the form of a rotary file more fully discolsed and claimed in my co-pending application entitled Rotary Manicuring Instrument, Serial No. 45,472, filed Aug. 21, 1948.

The instrument I6 is composed of a rotary discshaped head I! connected by a driven shaft assembly Hi to a casing 19 forming the hand piece of the instrument. The head I! 'has formed in the periphery thereof an annular recess I0 having a width suflicient for the insertion therein of an edge-portion of a finger nail to be manicured, and

for positioning of the edge of the nail against flle serrations formed in the base of the recess. The tool here shown is one of several rotary manicuring instruments which may be used with the machine. Another type of manicuring instrument is disclosed and claimed in my co-pending application, Serial No. 33,077, filed June 15, 1948, for Power Driven Manicuring Device, now forfelted.

The driven shaft assembly I 8 here includes a stem 2| extending axially from the rear side 22 of the head into an outwardly tapered stem portion 23 and a reduced threaded end 24 which is threaded into one end 26 of a shaft part 21 Journalled for rotation within the hand piece l9.

- Defined at the juncture between the tapered pora continuous external periphery over these sections, as illustrated in Figure 2. If desired, portions of the periphery of these members may be knurled to facilitate holding in the hand of the operator. The concentricity of th driven shaft 21 within the hand piece I9, and the shaft 44 within the section 59, provides an automatic insertion of the tongue 1| into the cross slot 12 upon threadably engaging the instrument hand piece into the end of the section 59. The threaded connection between sections 58 and 59 is intended to be a relatively tight one thereby retaining these sections together as a unitary chuck for the instrument casing.

As will be understood, the drive connection at both ends of the flexible drive is aflforded, by reason of the tongue and slot arrangement, a full floating axial movement. In the ordinary manipulation of the manicuring instrument in use and the corresponding relativ movement of the attached end of the flexible drive, a relative longitudinal displacement between the interior torsional drive element 31 and the sheath 33 ,takes place. In the present construction, this relative longitudinal movement of these parts of the drive shaft is freely permitted at the end connections and thereby the normal tendency of drive shafts of this character to whip or move inordinately within the hand of the user is practically completely eliminated. Also, by reason of the tongue and slot connection, a rapid attachment and detachment of the drive shaft to the motor may be effected, as well as a rapid attachment and interchange of manicuring instruments at the opposite end of the drive shaft.

As another feature of importance of the drive shaft, longitudinal strain in the drive shaft, as may be occasioned by a direct pulling on the shaft, is taken up by the interior drive element 31. As will be understood, the sheath 83, by reason of its construction above described, will permit limited longitudinal distension and such action will draw the shoulders 53 and 61 of the shaft parts against the shoulder 52 in the end member 4| and against the end 68 of the end section 58, whereby further elongation of the drive shaft is prevented by the interior drive element 31, which, as above described, is strongly resistant to elongation. In this manner, damage to the outer sheath by reason of an unusual longitudinal force applied thereto is prevented by the support of the sheath against such longitudinal strain afforded by the interior element 31.

I claim:

Means for coupling a flexible drive composed 6 of a flexible outer sheath and an interior flexible drive element to an electric motor housing and shaft and to a rotary manicuring device comprising, a rigid tubular member connected at one end to said outer sheath and at the other end to said motor housing and having an axial bore therethrough, said bore having an enlarged portion adjacent one end thereof, a shaft part secured at one end to said flexible drive element and provided with means for slidable connection to said motor shaft at its opposite end for joint rotation therewith and having an enlarged cylindrical por tion journalled for rotation and limited longitudinal reciprocation in said enlarged bore portion. said enlarged bore portion and said cylindrical portion being dimensioned to provide a bearing surface for said shaft part, a second rigid tubular member secured at one end to said outer sheath and provided with means for connection to said manicuring device at its opposite end and having an axial bore therethrough, said bore having an enlarged portion substantially medially of its length, a second shaft part secured at one end to said flexible drive element and having a slidable connection to said manicuring device for joint rotation therewith, said second shaft having an enlarged cylindrical portion adjacent one end thereof journalled for rotation and limited longitudinal reciprocation in said enlarged bore, the portions of said shaft part adjacent each side of said enlarged cylindrical portion being journalled for rotation in said bore whereby a three point bearing arrangement is provided at the connection between said flexible drive element and said manicuring device for smooth, non-vibrational rotation thereof.

MERRILL KESSLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,324,787 Berge Dec. 16, 1919 1,386,161 Clifford Aug. 2, 1921 1,555,647 Falconer July 14, 1922 2,222,613 Green Nov. 26, 1940 2,235,189 Westner Mar. 18, 1941 FOREIGN PATENTS Number Country Date 407,913 Germany June 23, 1923 857,527 France Sept. 7, 1940 

